AMPK as a redox sensor and modulator

AMPK 作为氧化还原传感器和调制器

• 批准号: 7638516
• 负责人: MING-HUI ZOU
• 金额: $ 36.63万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7638516
• 关键词: 3-nitrotyrosine; 5' -AMP-activated protein kinase; Abbreviations; Acetylcholine; Actins; Address; Adenoviruses; Adipocytes; Adverse effects; Aging; Antibodies; Antioxidants; Aorta; Apolipoprotein E; Arachidonic Acids; Arterial Fatty Streak; Atherosclerosis; Biological Assay; Biology; Blood; Blood Vessels; CaM kinase I activator; Cardiovascular Diseases; Cardiovascular system; Catalytic Domain; Cell Adhesion Molecules; Cells; Cerebrum; Cholesterol; Chronic; Coronary; Cyclic GMP; Data; Detection; Development; Diabetes Mellitus; Dimensions; Disease; Dominant-Negative Mutation; E-Selectin; Endothelial Cells; Endothelium; Energy Metabolism; Environmental Tobacco Smoke; Enzymes; Epoprostenol; Equilibrium; Etiology; Eukaryotic Cell; Event; Exhibits; Exposure to; Functional disorder; Generations; Genetic; Glucose; Goals; Health; Hepatocyte; Human; Hypertension; Hypertriglyceridemia; Hypoxia; ICAM1 gene; Incubated; Inflammation; Inflammatory; Ischemic Preconditioning; Knock-out; Knockout Mice; Lesion; Link; Lipid Peroxidation; Lipids; Mediating; Medicine; Metabolism; Metformin; Modeling; Molecular; Motion; Mus; NADPH Oxidase; NG-Nitroarginine Methyl Ester; Nicotine; Nicotinic Receptors; Nitric Oxide; Obesity; Oxidants; Oxidases; Oxidation-Reduction; Peripheral; Peroxonitrite; Phenotype; Phosphotransferases; Physiological; Plasma; Play; Polyethylene Glycols; Process; Production; Prostacyclin synthase; Prostaglandins; Prostaglandins I; Protein Kinase C; Protein-Serine-Threonine Kinases; Rattus; Reaction; Reactive Nitrogen Species; Reactive Oxygen Species; Relative (related person); Relaxation; Resistance; Risk Factors; Role; Signal Transduction; Smoke; Smoker; Smoking; Smooth Muscle; Stimulus; Stress; Superoxide Dismutase; Superoxides; System; Thromboxane Receptor; Transgenic Mice; Triglycerides; Tyrosine; Vascular Cell Adhesion Molecule-1; Western Blotting; Whole Organism; Wild Type Mouse; acetovanillone; arginine methyl ester; atherogenesis; biological adaptation to stress; cardiovascular disorder risk; cardiovascular risk factor; catalase; cell growth regulation; cigarette smoking; cigarette smoking; exposed human population; genetic manipulation; human CYBA protein; human NOS3 protein; hypercholesterolemia; imidazole-4-carboxamide; improved; in vivo; inhibitor/antagonist; insight; mouse model; mutant; neutrophil cytosol factor 67K; novel; overexpression; oxidant stress; polyethylene glycol-superoxide dismutase; premature; prevent; progesterone 11-hemisuccinate-(2-iodohistamine); promoter; public health relevance; response; riboside; sensor; stressor; tetrahydrobiopterin; therapeutic target

DESCRIPTION (provided by applicant): AMPK is a serine/threonine protein kinase involved in the regulation of cellular and organismal metabolism. The AMPK system acts as a sensor of cellular energy status that is conserved in all eukaryotic cells. AMPK has been suggested to serve as an energy gauge in cells, by detecting changes in the ratios of AMP to ATP. The consequences of AMPK activation include inhibition of ATP-consuming processes and activation of an ATP-producing process. The applicant's group was the first to demonstrate that physiologically relevant concentrations of ONOO- increased AMPK activity as well as its downstream enzymes such as eNOS and acetyl Co-A carboxylase (ACC). In addition, we have also demonstrated that ONOO--dependent AMPK activation is operative in hypoxia-reoxygenation, metformin- stimulated endothelial cells, thromboxane receptor stimulation, and nicotine-treated adipocytes. Similarly, we found that nicotine, a major constituent of cigarette smoke, activates AMPK in differentiated 3T3L1 adipocytes in a ROS-dependent fashion. Interestingly, AMPK activation by pharmacological AMPK activators (AICAR and metformin), physiological stimuli (glucose-depletion and osmotic stress), or genetic manipulation (adenoviruses encoding constitutively active AMPK) protects the endothelium against the adverse effects of nicotine. Concomitantly, pharmacological or genetic inhibition of AMPK markedly increased ROS, NF?B, and inflammatory genes (ICAM-1, VCAM-1, and E-selectin) in cultured endothelial cells, differentiated 3T3L1 adipocytes, and cultured primary rat hepatocytes. In parallel, in supporting that AMPK functions as a suppressor of oxidant stress, we have obtained preliminary evidence suggesting that AMPK activation by ischemic preconditioning (IPC) effectively blocked hypoxia/reoxygenation-triggered oxidant stress. The most conclusive evidence that AMPK reduced oxidant stress is that IPC failed to alter both the markers of oxidant stress and endothelial function in the AMPK 11 knockout (KO) mice. Consistently, we have found that compared to the wild types, aortas isolated from AMPK 11 or 12 KO mice exhibited impaired endothelial relaxation together with increased detections of both O2.- and ONOO-. Similarly, there was greater levels of NADPH oxidase subunits including gp91phox (NOX2), NOX-4, p22phox, p47phox, and p67phox together with increased NAD(P)H oxidase activity in AMPK12 KO mice than those in C57BL6 wild types. Importantly, apocynin, a potent NAD(P)H oxidase inhibitor, restored acetylcholine-induced endothelium-dependent relaxation in AMPK 12 KO mice, further suggesting NAD(P)H oxidase is functionally active and is responsible for impaired endothelial function in AMPK 12KO mice. Finally, without altering plasma lipids (cholesterol and triglyceride), the aortas isolated from Apo-E/AMPK11 or AMPK/AMPK 12 dual KO mice exhibited increased detection of oxidant stress markers, increased atherosclerotic lesions, and increased expression of proinflammatory adhesion molecules when compared to those in Apo-E KO mice. The goal of this application is to establish (a) that AMPK, through its ability to respond to very small changes in AMP levels, may be the proximal "oxidant stress-sensor" of the cell; (b) that AMPK activation may trigger physiological responses to suppress processes that generate oxidants (modulator) and or increase anti-oxidant defense systems; and (c) AMPK, via a reduction of oxidant stress, maintains the non-angiogenic, non-inflammatory, and atherosclerosis-resistant phenotypes in vascular cells. PUBLIC HEALTH RELEVANCE: A basic premise of this proposal is that AMPK activation could protect cells and the whole organism against the adverse effects of cardiovascular risk factors such as nicotine by setting in motion events that decrease oxidant stress. For the sake of clarity and being focused of the current application we use nicotine as a pathological stimulus relevant to cardiovascular diseases. As there is growing evidence that oxidant stress is involved in the vascular effects of cardiovascular risk factors including hypercholesterolemia, diabetes, and hypertension, thus, the significance of this proposal is beyond nicotine and will be applicable to other cardiovascular diseases. The current application addresses a fundamental question in biology and medicine, i.e., how oxidant stressors are sensed and modulated in health and disease. Completion of this application, thus, may add an entirely new dimension to the role of AMPK in stress responses and provide an interface between oxidant stress, energy metabolism, and cardiovascular biology. Completion of the proposed studies will provide novel insights into whether AMPK is a potential target for therapy in smoking and common diseases including aging, obesity, diabetes, hypertension, and atherosclerosis.

说明（由申请人提供）：AMPK是一种丝氨酸/苏氨酸蛋白激酶，参与细胞和生物体代谢的调节。AMPK系统作为细胞能量状态的传感器，在所有真核细胞中是保守的。AMPK被认为是细胞中的能量计，通过检测AMP与ATP比率的变化。AMPK激活的结果包括抑制ATP消耗过程和激活ATP产生过程。申请人的小组首次证明生理相关浓度的ONOO-增加AMPK活性以及其下游酶如eNOS和乙酰辅酶A羧化酶（ACC）。此外，我们还证明了ONOO-依赖性AMPK激活在缺氧-复氧、二甲双胍刺激的内皮细胞、血栓素受体刺激和尼古丁处理的脂肪细胞中起作用。同样，我们发现尼古丁，香烟烟雾的主要成分，激活AMPK在分化的3 T3 L1脂肪细胞中的ROS依赖的方式。有趣的是，药理学AMPK激活剂（AICAR和二甲双胍）、生理刺激（葡萄糖耗竭和渗透压）或遗传操作（编码组成型活性AMPK的腺病毒）激活AMPK可保护内皮细胞免受尼古丁的不良影响。同时，药理学或遗传抑制AMPK显着增加ROS，NF？B和炎症基因（ICAM-1，VCAM-1和E-选择素）在培养的内皮细胞，分化的3 T3 L1脂肪细胞，和培养的原代大鼠肝细胞。同时，在支持AMPK作为氧化应激的抑制剂的功能，我们已经获得了初步的证据表明，AMPK激活缺血预处理（IPC）有效地阻断缺氧/复氧触发的氧化应激。AMPK降低氧化应激的最确凿证据是IPC未能改变AMPK 11敲除（KO）小鼠中的氧化应激标志物和内皮功能。因此，我们发现与野生型相比，从AMPK 11或12 KO小鼠中分离的血管内皮细胞表现出内皮舒张受损，同时O2-。和ONOO-。类似地，AMPK 12 KO小鼠中NADPH氧化酶亚基（包括gp 91 phox（NOX 2）、NOX-4、p22 phox、p47 phox和p67 phox）的水平高于C57 BL 6野生型小鼠，同时NAD（P）H氧化酶活性增加。重要的是，夹竹桃苷，一种有效的NAD（P）H氧化酶抑制剂，恢复了AMPK 12 KO小鼠中乙酰胆碱诱导的内皮依赖性舒张，进一步表明NAD（P）H氧化酶在功能上是活性的，并且是AMPK 12 KO小鼠中内皮功能受损的原因。最后，在不改变血浆脂质（胆固醇和甘油三酯）的情况下，与Apo-E KO小鼠相比，从Apo-E/AMPK 11或AMPK/AMPK 12双KO小鼠分离的动脉粥样硬化表现出氧化应激标志物的检测增加、动脉粥样硬化病变增加和促炎性粘附分子的表达增加。本申请的目的是确定（a）AMPK通过其响应AMP水平的非常小的变化的能力，可能是细胞的近端“氧化应激传感器”;（B）AMPK激活可以触发生理反应以抑制产生氧化剂的过程（调节剂）和/或增加抗氧化防御系统;和（c）AMPK，通过减少氧化应激，维持血管细胞中的非血管生成、非炎性和抗动脉粥样硬化表型。公共卫生相关性：该提议的基本前提是AMPK激活可以通过设置减少氧化应激的运动事件来保护细胞和整个生物体免受心血管风险因素（如尼古丁）的不利影响。为了清楚起见，并且为了集中于本申请，我们使用尼古丁作为与心血管疾病相关的病理刺激。随着越来越多的证据表明氧化应激参与了包括高胆固醇血症、糖尿病和高血压在内的心血管危险因素的血管效应，因此，该提议的意义超出了尼古丁，将适用于其他心血管疾病。本申请解决了生物学和医学中的一个基本问题，即，氧化应激源是如何在健康和疾病中被感知和调节的。因此，完成这一应用，可能会增加一个全新的层面AMPK在应激反应中的作用，并提供氧化应激，能量代谢和心血管生物学之间的接口。完成拟议的研究将提供新的见解AMPK是否是一个潜在的目标，治疗吸烟和常见疾病，包括衰老，肥胖，糖尿病，高血压和动脉粥样硬化。